Hyper-Q Trace Log File
The Hyper-Q trace log file contains event trace messages. Each line in the trace log file corresponds to a tracer event that is published during the execution of a query.
Several Hyper-Q components publish events, and each event corresponds to a particular client request within a client session. Events can also correspond to a particular backend request. Additionally, events may also correspond to a given log sequence number (LSN) if their session is part of a bulk job, though for normal sessions the LSN field will show a default value of 0.
Every tracer event includes both a tag category and a tag name.
The tag category is an indicator of the type of event, and includes labels such as Preprocessing, Emulation, and Results. The tag category is useful as a filtering mechanism, in case you’re interested in a particular stage of query processing, though it may also be useful as an indicator of when different stages start and end.
The tag name is a more specific label, and indicates what the particular event is for. The tag name is useful for getting a more fine-grained window into the handling of a given query. Events may also include a tag value, which contains additional information about that event. For example, the Start Client Query event includes the text of the client query as the tag value for that event.
Hyper-Q Trace Log Format
The Hyper-Q trace log file is a comma-separated values (CSV) file, a delimited text file that uses a comma to separate values. Each line of the file is a data record. Each record consists of one or more fields, separated by commas.
Column Name | Description |
|---|---|
Time | The timestamp when the event occurred, using the local server timezone and formatted with millisecond-precision timestamps as: YYYY-MM-DD HH:MM:SS.mmm |
Session ID | The integer session identifier for the session to which the event belongs. |
Client Request ID | The universally unique identifier (UUID) identifier for the current client request. |
Backend Request ID | The UUID for the current backend request, if applicable. |
LSN | An ID generated for bulk jobs that use multiple, parallel sessions. Typically, these connect different sessions with distinct session IDs that are part of the same job. |
Tag Category | The tracer event category formatted as both a numeric code prefixed with |
Tag Name | The tracer event name, formatted as both a numeric code prefix with |
Tag Value | The tracer tag value (if included in the event). This value is free-form, and may span multiple lines, with the meaning of the value dependent on the particular event. |
Hyper-Q Trace Log Categories
Hyper-Q logs the following categories in the trace log.
Category Code | Category Name |
|---|---|
DLC002 | Pre-processing |
DLC003 | Execution |
DLC004 | Results |
DLC005 | Metadata |
DLC006 | Logic processing |
DLC007 | Fast export |
DLC008 | Feature extraction |
DLC009 | Emulation |
DLC010 | Debug |
Hyper-Q Trace Log Events
Hyper-Q logs the following events.
Event Code | Event Name | Verbosity |
|---|---|---|
DLE0003 | Start Client Query | 2 |
DLE0055 | Start XC Request Handling | 5 |
DLE0004 | Start Binding | 5 |
DLE0005 | Start Transformation | 5 |
DLE0006 | Start Serialization | 5 |
DLE0007 | Start Data Conversion | 2 |
DLE0008 | Query Sent to Backend | 2 |
DLE0009 | Query Completed | 2 |
DLE0010 | Error | 1 |
DLE0011 | Start Catalog Lookup | 4 |
DLE0012 | Catalog Lookup Completed | 4 |
DLE0013 | Start MD-Store Lookup | 4 |
DLE0014 | MD-Store Lookup Complete | 4 |
DLE0019 | Start Transaction Abort | 2 |
DLE0021 | Start Parameterized Query | 5 |
DLE0023 | Initialize MD-Store Update | 4 |
DLE0024 | MD-Store Update Complete | 4 |
DLE0025 | Intermediate Query Response Received | 3 |
DLE0026 | Fetch Chunk Complete | 5 |
DLE0027 | Start TDF Cursor Query | 4 |
DLE0028 | TDF Cursor Query Complete | 4 |
DLE0029 | Query Cancelled | 4 |
DLE0030 | Row Count | 4 |
DLE0031 | Bulk Load Session | 1 |
DLE0032 | Start MD-Store Update | 4 |
DLE0033 | Client Query Hash | 2 |
DLE0034 | CTAS with UPI | 4 |
DLE0035 | DML with Quantified Subquery | 4 |
DLE0036 | Emulate Sequence | 4 |
DLE0037 | Enforce SET Table INSERT | 4 |
DLE0038 | UPI INSERT | 4 |
DLE0039 | UPI UPDATE | 4 |
DLE0040 | UPDATE with Join | 4 |
DLE0041 | UPDATE Temp Table in Xact | 4 |
DLE0042 | SET Table INSERT | 4 |
DLE0043 | SET Table INSERT Values | 4 |
DLE0044 | MERGE | 4 |
DLE0045 | SET Table UPDATE | 4 |
DLE0046 | MLOAD Uniqueness Check | 4 |
DLE0048 | Materialize GTT | 4 |
DLE0049 | Eliminate Nested Case Expressions | 4 |
DLE0050 | Quantified Subquery With Long Const List | 4 |
DLE0051 | Start Fetch Chunk | 5 |
DLE0053 | DEBUG | 4 |
DLE0054 | Client Query Config | 2 |
DLE0060 | Query Type Select | 2 |
DLE0061 | Query Type DDL | 2 |
DLE0062 | Query Type DML | 2 |
DLE0063 | Query Type Other |